"""
Array Backed Grid Shown By Sprites

Show how to use a two-dimensional list/array to back the display of a
grid on-screen.

This version syncs the grid to the sprite list in one go using resync_grid_with_sprites.
This is faster than rebuilding a shape list every time the grid changes,
but we are still inspecting every single cell of the grid when it updates.
There are faster ways, but this works for smaller grid sizes.

If Python and Arcade are installed, this example can be run from the command line with:
python -m arcade.examples.array_backed_grid_sprites_1
"""
import arcade

# Set how many rows and columns we will have
ROW_COUNT = 15
COLUMN_COUNT = 15

# This sets the WIDTH and HEIGHT of each grid location
WIDTH = 30
HEIGHT = 30

# This sets the margin between each cell
# and on the edges of the screen.
MARGIN = 5

# Do the math to figure out our screen dimensions
WINDOW_WIDTH = (WIDTH + MARGIN) * COLUMN_COUNT + MARGIN
WINDOW_HEIGHT = (HEIGHT + MARGIN) * ROW_COUNT + MARGIN
WINDOW_TITLE = "Array Backed Grid Example"


class GameView(arcade.View):
    """
    Main application class.
    """

    def __init__(self):
        """
        Set up the application.
        """
        super().__init__()

        # Create a 2 dimensional array. A two dimensional
        # array is simply a list of lists.
        # This array can be altered later to contain 0 or 1
        # to show a white or green cell.
        #
        # A 4 x 4 grid would look like this
        #
        # grid = [
        #     [0, 0, 0, 0],
        #     [0, 0, 0, 0],
        #     [0, 0, 0, 0],
        #     [0, 0, 0, 0],
        # ]
        # We can quickly build a grid with python list comprehension
        # self.grid = [[0] * COLUMN_COUNT for _ in range(ROW_COUNT)]
        # Making the grid with loops:
        self.grid = []
        for row in range(ROW_COUNT):
            # Add an empty array that will hold each cell
            # in this row
            self.grid.append([])
            for column in range(COLUMN_COUNT):
                self.grid[row].append(0)  # Append a cell

        # Set the window's background color
        self.background_color = arcade.color.BLACK
        # Create a spritelist for batch drawing all the grid sprites
        # 创建精灵列表
        self.grid_sprite_list = arcade.SpriteList()

        # Create a list of solid-color sprites to represent each grid location
        for row in range(ROW_COUNT):
            for column in range(COLUMN_COUNT):
                x = column * (WIDTH + MARGIN) + (WIDTH / 2 + MARGIN)
                y = row * (HEIGHT + MARGIN) + (HEIGHT / 2 + MARGIN)
                # 创建精灵，SpriteSolidColor创建的是方形精灵
                sprite = arcade.SpriteSolidColor(WIDTH, HEIGHT, color=arcade.color.WHITE)
                sprite.center_x = x
                sprite.center_y = y
                self.grid_sprite_list.append(sprite)

    def resync_grid_with_sprites(self):
        """
        Update the color of all the sprites to match
        the color/stats in the grid.

        We look at the values in each cell.
        If the cell contains 0 we assign a white color.
        If the cell contains 1 we assign a green color.
        """
        # 根据矩阵数据，变更精灵的颜色
        for row in range(ROW_COUNT):
            for column in range(COLUMN_COUNT):
                # We need to convert our two dimensional grid to our
                # one-dimensional sprite list. For example a 10x10 grid might have
                # row 2, column 8 mapped to location 28. (Zero-basing throws things
                # off, but you get the idea.)
                # ALTERNATIVELY you could set self.grid_sprite_list[pos].texture
                # to different textures to change the image instead of the color.
                # 计算精灵的偏移量，实际就是一维数组的索引
                pos = row * COLUMN_COUNT + column
                if self.grid[row][column] == 0:
                    self.grid_sprite_list[pos].color = arcade.color.WHITE
                else:
                    self.grid_sprite_list[pos].color = arcade.color.GREEN

    def on_draw(self):
        """
        Render the screen.
        """
        # We should always start by clearing the window pixels
        self.clear()

        # Batch draw all the sprites
        # 批量绘制精灵
        self.grid_sprite_list.draw()

    def on_mouse_press(self, x, y, button, modifiers):
        """
        Called when the user presses a mouse button.
        """

        # Convert the clicked mouse position into grid coordinates
        column = int(x // (WIDTH + MARGIN))
        row = int(y // (HEIGHT + MARGIN))

        print(f"Click coordinates: ({x}, {y}). Grid coordinates: ({row}, {column})")

        # Make sure we are on-grid. It is possible to click in the upper right
        # corner in the margin and go to a grid location that doesn't exist
        if row >= ROW_COUNT or column >= COLUMN_COUNT:
            # Simply return from this method since nothing needs updating
            return

        # Flip the location between 1 and 0.
        if self.grid[row][column] == 0:
            self.grid[row][column] = 1
        else:
            self.grid[row][column] = 0

        # Update the sprite colors to match the new grid
        # 同步：根据矩阵，变更精灵的属性
        self.resync_grid_with_sprites()


def main():
    """ Main function """
    # Create a window class. This is what actually shows up on screen
    window = arcade.Window(WINDOW_WIDTH, WINDOW_HEIGHT, WINDOW_TITLE)

    # Create the GameView
    game = GameView()

    # Show GameView on screen
    window.show_view(game)

    # Start the arcade game loop
    arcade.run()


if __name__ == "__main__":
    main()